Serious traffic accident. Drivers... one seriously injured, the other a little less.
When the ambulance arrived, the doctor notices shocked that the slightly injured driver was engaged in anal sex with the seriously injured driver and he desperately howls:
-What are you doing, sir, are you crazy?
-No... I only give him the first aid!
-Well first aid is granted by "mouth to mouth" ...
-That's how we started, but we got a little horny!