When I play Pick-up Soccer Games I Get Sexually Harrased?

I am a really good female soccer player, so I decided to play with boys to get better. The only problem is they are harrasing me. When they make a tackle, they hump me in the . They grope my whenever possible. One of the shy players even had a ***** while playing. I really want to get better, but playing like this is really freaking me out. Please help.