Term used to describe the act of having sex in semi-public places, usually after hours or in vacant facilites, and causing a fair property damage in that act.
Sexual vandalism takes mere al fresco sex a step further by adding the thrill of wanton hooliganism.
Note that to sexually vandalise a person could have a completely different meaning to that of doing it to various public property.
me and my girlfriend broke into her school the other night to enjoy a bit of sexual vandalism of account of her graduating from that place soon. we romped all over and broke 2 sinks in the men's bathroom, ended up cracking the glass of their photocopier, moved all the potted plants into the entrance lobby and spay painted cocks on all the notice boards in the halls.