4. Overstaying your welcome. The first time you have sex with a guy, it will likely bring up a variety of emotions for both of you. Though it might be your initial instinct, don’t deal with those emotions by being overly clingy (just like you wouldn’t want a guy to be too clingy with you). If you’re at his house, spend some time hanging out with him in the morning, but don’t stick around all afternoon, especially if it looks like he’s trying to get on with his day and do other things. After you’ve gotten out of bed and maybe had some breakfast, tell him you have to take off, but that last night was a lot of fun. Leaving of your own accord shows that you have other priorities in your life aside from him, and that those priorities haven’t changed just because you’ve slept together.