The teen has had more than one cock several times, actually she no longer fucks normally but always likes to fuck with at least two cocks, so threesomes are almost standard for her. So it fits perfectly that the two guys from the tennis club access her as soon as they hear the new one in the club wants her holes plugged in a threesome. Threesome is already normal for her, so it is not surprising that she also likes to be fucked in the ass and the guys should take her anal hard to make everything perfect.