Transcript: You know you should wear a condom.  But how do you convince your penis of that?  Putting on a condom can be scary—what if she backs out, the mood is ruined, or you lose your erection? Relax.  First, ensure that you keep condoms in an easy-access place that’s not too obvious.  For example, try a small, inconspicuous toiletries bag near the bed.
If you’re out, keep a condom in the chest pocket of your jacket where it will be safe and unnoticed.  When it’s time to open the condom, make it easy by tearing from the center, not the corner.  
When putting the condom on, get on the bed and kneel on both knees, bending slightly forward.  This is effective because blood will rush to your penis and offset any nervous shrinking.  Of course, it has the added bonus of leaving you in position to,…well, take the plunge!