Whether your libido is a convenient Mini Cooper, a sexy Lexus or a trusty, reliable Ford pickup, you’re bound to get a flat eventually. But in order to keep yourself out of permanent park, it’s important to understand what deflates our sex drives.

Stress. If you have to write in your datebook “Sex—8 p.m.,” chances are you won’t be having the longest-lasting post-dinner-dishes sex. Unless you get off on bill paying, having too much on your plate won’t inspire you to lick it clean at the end of the day.

Good sex requires you to be mentally present (making tomorrow’s to-do list in your head doesn’t count as fantasizing). Exercise promotes mental clarity and physical stamina so you can make the head-space for sex and resist physically shutting down under pressure.

Last year’s fight. Most require emotional closeness for sexual desire. While makeup sex after a blow-out fight can be hot, steaming over an ancient, unresolved betrayal is not. Talk it out if you want to rock it out.

Gettin’ wasted. A drink can lube up a rusty piston, but getting hammered is never sexy, especially if your partner’s on a different sobriety level. If you need to be in an altered mental state in order to have sex, it’s time to get a counselor.

*Yawn.* Showing up to work exhausted with ill-concealed hickies on your neck is fun! But zombie-shuffling into the house after four hours’ sleep and a long work day won’t get you laid. Stellar sex requires the physical energy to pull it off. If your lady is giving you a lap dance in her brand new lingerie and you’re still waffling between head and bed, it’s time to make a full eight hours your priority. Plus hitting the hay early with your sweetie could organically spark some sleepy shenanigans.

Poopy diapers. Stupid babies and their basic survival needs! Now’s the time to bust out the dayplanner and schedule yourself some sexytime during baby’s nap. See past column “What to Sexpect When You’re Expecting” (February 3, 2011) and read Love in the Time of Colic by Ian Kerner and Heidi Raykeil for tips on how to be hot mamas and papas.

Poppin’ ‘scripts. Sometimes your physical and mental wellbeing needs to take priority over your sex life. From anti-depressants to antihistamines, medications can shoot your libido in the… foot. Take the pressure off yourselves to have the same sex life you once did and avoid the blame game. Your physical “shortcomings” are being controlled by outside substances, not anything you or your partner are doing wrong. Experiment with different ways of being intimate or seek some professional advice.

Wompy McWomperson. Low self-esteem and depression go hand in hand and are detrimental to everyone’s libido. No one wants to get sexy if they’re not feeling sexy. Reassure a wompy partner that you find them desirable. Again, staying active and eating healthily will improve your self-image and sex drive. However, if these feelings are coming from an abusive partner instead of from within, only dumping the asshole will solve the problem, not treadmill time.

Erectile dysfunction and menopause. OMG, you’re so dysfunctional! Actually, it’s pretty normal that with age, illness or injury, your body will want to take a rest even if your mind doesn’t. Low sex drive and ED/menopause are cyclical friends, with one encouraging the other and vice versa. Men-Oh-Oh-Pause has juicy advice while an upcoming column will keep your soldier’s attention.

Bachelor marathons. Focusing on the end goal of penetration can distract from maintaining the foundation of good sex —intimacy. Telling yourself to hurry up and get in the mood won’t make anyone wet any faster. Go on a date. Make out on the couch. Warm fuzzy feelings of intimacy can quickly turn into some warm, fuzzy sex (or something). Turn it off to turn it on—couples that have a TV in their bedroom have 50 percent less sex than those who don’t.

None of these libido killers ringing any bells? Dig deeper. Maybe you’re not sexually attracted to your partner at all. You can love her/him, enjoy her company and work well together, but if the sex spark isn’t there, you’re just roommates. And no one can fix that tire.