Don't go condomless with a plate... Because she's a fucking plate. But when you finally decide to go condomless with your long-term–relationship (after checking that she hasn't gotten several STI's from her probable carousel riding) there's something you can do to avoid the risk of a not-so-accidental pregnancy for the rationally risk-averse:

Regularly bathing your nuts in a hot bath (but not painfully hot) reduces your sperm count considerably, and if you do it enough, makes you sterile for like 4 months.

"It turns out that sperm don't like heat and by bathing, or simply submerging the testes, in 116 degrees water (just below the pain threshold) for forty five minutes each day for 21 days, a male becomes sterile for the next six months. Doing this at 110 degrees reliably produces sterility for the next four months and either way, it can be repeated for continued effectiveness when the allotted time is up. This method dates back to the writings of Hippocrates and derives its effectiveness from the fact that sperm needs to be several degrees cooler than body temperature to be viable; this is why they hang outside the body. Actually, sperm cell death happens at 95 degrees F, while normal cell death happens at 108 degrees F - so this method effectively kills the sperm for a limited but extended period of time."

http://www.naturalnews.com/029126_birth_control_papaya.html#ixzz3hHCispyN

"In studies on men in the United States and Japan, the effect of heat on sperm production has been demonstrated very clearly. If the testes are exposed daily for three days to a temperature of 45 C (113F) for about fifteen minutes, the sperm count falls to very low levels and does not return to normal for about fifty days. If exposure is made at intervals of about two weeks, the sperm count can be held at low levels."

http://www.puzzlepiece.org/bcontrol/kiser1962.html

Decided to research it after watching an ArtOfManliness video on the value of cold showers on increased sperm count, where he briefly mentioned that hot showers decrease sperm count... By like a shitload.

Obviously research the fuck out of this yourself before doing it.

Food for thought.