More than one in five women will be sexually assaulted while in college. Most of them—around 80 percent—will know their attackers. One recent survey of 379 male undergraduates at a large public university found that more than half of survey respondents who played sports reported coercing a partner into sex. Among types of coercion cited was "I used threats to make my partner have oral or anal sex." That same survey found that 38 percent of non-athletes said they used verbal or physical pressure for sex, and the researcher found a link between those coercive behaviors and attitudes like "If a woman doesn't fight back, it isn't rape."
Do not do this.
Chances are, you're a nice person. You don't think you're going to be a rapist. But much of the training you've had up until now is working against you. You've been told sex happens without communication, that women are trophies or "bases" to be collected or passed, and that rape is what happens when a stranger jumps out from the bushes and not when a "nice guy" takes advantage of a drunk friend. Reject all of this. It is complete bullshit.
Treat your sexual partners like human beings. Use your words. Ask them clearly if they want to have sex with you. If they say no, don't. If they don't say anything at all, don't. If they're too drunk to answer you clearly, don't. If they said "yes" earlier but now they're saying "no," don't. Even if you just really, really want it—still no. It is not your right to keep asking or threaten them until they say yes. Consent that is the result of coercion is not really consent. (Sound too awkward? Does it seem like talking about it is going to "ruin the mood"? Guess what ruins the mood more than an awkward conversation? Being a fucking rapist.)
If you see a friend who may be in danger, say something. If you hear friends talking about trying to coerce people into having sex with them or sleeping with people who were blacked out or passed out, say something. If you or someone you know has been assaulted, find resources on your campus (washington.edu/sexualassault, seattleu.edu/caps/resources, seattlecolleges.edu/hr/student_sd.aspx) or contact the King County Sexual Assault Resource Center (kcsarc.org, 24-hour resource line: 888-998-6423).