spice up sex ??

Me and my boyfriend when we first got together couldn't keep our hands off each other and now it seems like es kind of bored, he talks a lot about a 3 some which I would do but don't know how to go about gettin another female, and Iv tried all the tricks I can think of when having sex or giving him oral, so does anyone else have any good tricks up there sleeve on how to spice up our sex life ?