April Fools' Day can feel like a guy's version of Valentine's Day. It's the one special time year when you can indulge in what makes you feel closest to your girl, albeit through pranks instead of presents.

She might have a sense of humor and appreciate practical jokes, but that doesn't give you a free pass to go too far. Here's how your holiday can turn into her hell (and by extension, your hell) faster than you can say "April fools'!"

Messing with her appearance

Even if she's low-maintenance, never assume that it's OK to undo whatever work she put into how she looks. It's not about vanity; it's about respecting her time, some of which she probably spent on her hair. It might seem like a great idea to put glue in her conditioner, but for her sake -- and yours -- go with a different one.

Fake cheating

A huge don't for both boyfriends and girlfriends. Even the pretend, temporary implication that you're cheating is asking for disaster. Not only are you forcing the other person to entertain the worst idea, you're doing it for your own amusement. It's not so much of a prank as it is a lapse in judgment that you'll absolutely regret.

Fake proposing

You risk getting into so much trouble that the only way to get out of it is ACTUALLY getting engaged, and that's really only a prank on yourself.

Scaring the crap out of her

Admit it. Freaking your girlfriend out is fun and it's easy ... but the odds are that she's with you because she feels safe and comfortable with you, and messing with that may not be in your best long-term interests. Ultimately there's a line with scaring her, and crossing it can make it seem like you don't care.

Fake dumping her (or anything else that makes her cry)

Sometimes it's not clear that you've made a huge mistake until your girlfriend is crying, but if she is, it's game over. It doesn't matter how good of an idea you thought it was or if you think she's overreacting; defending the prank over her feelings will only make you look like the bad guy. Jump ship while you still can.

Assuming she'll "get over it" right away

Your girlfriend's inability to forget is on par with the old adage about elephants never forgetting. Give her some time and space to cool off about it. Getting immediately frustrated that she "can't take a joke" will only make things worse.

Putting more thought into the prank than you put into your actual relationship

When you're really into practical jokes, it's hard not to look at an angry girlfriend as a marker of a job well done. You want a girl with a sense of humor who appreciates yours, but you're also competitive and want to top your past pranks. Don't be so concerned with winning that you risk losing your relationship. Play it safe and stick to intricately pranking your buddies.