I think that L is the one you need to use condoms with, and it is highly unreasonable of her to ask or expect you to break your fluid bond with T&J just so she can feel more important to you than they are (it is also a bit arrogant - though arrogance often stems from insecurity) .
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein