So far, yes and it also bans you from the pure romantic path. It kinda makes sense that Lena gets upset about it even if Ian tells her that it was only that time (lying or not) and that it was before they were a couple. It's not only jealously because you fucked another girl (even if you technically weren't cheating), you fucked one of your friend's girlfriend in the middle of the street and hide it from your friends, that's quite scummy. So in that situation that Lena doesn't break up with you but it's not happy with you at all, Ian might think is not the right moment to gift her the necklace.