Sounds like the brother needs to bust a nut. Here's some advice from the other side of the pond. I call it "fractionation" after the hypnosis principle. Say you're making out, eventually, you just put your hand on her tit. If she doesn't move it away, great. At some point you put your hand under her shirt, or begin unbuttoning, or whatever. If she stops you. You stop. If she says, "We shouldn't be doing this." You go along with it, "Yeah, you're right, we shouldn't." Or, you do a freeze-out (very effective). The point is, you go back to it later, like in 15 minutes. Each time she'll let you go further and further, like in hypnosis when you fractionate, they go deeper and deeper. Before you know it, you're inside her, "filling up her gas tank" and she has a fake name for you so that you can avoid the paternity issue.