I'd like to ask again, is it possible at all that in the future we could get the option to date several(or maybe all) LI? It kind of broke my heart when Lise commented on me getting close with Tessa (Altho I realise she's probably just teasing and not jealous.).
You will actually be able to do that. Yes, you will pick (or not, depending on you) your main LI during their Day 3. But that does not lock you out of other ladies' content. It means two things: 1) During the main storyline, you will get extra scenes with your main LI, and 2) You will get her special ending. But no locking out of 99% of the content. There won't be no negative impact on the player for slutting around (but on the other hand, you'll be able to fully commit to just one of them if you wish). Like I said before, all ladies are adult futas who know what their (fem)boys need.
Besides, I always wanted SP to be a comfy game, so there won't be any jealousy or any kind of emotional/relationship drama. Otherwise, as a rule of thumb: if you are not sure about what Lise tells you, she is making banter.