LS, the way you handled the text situation was great

It's hard dealing with situations like that!
Thanks. It was like traveling through a mine-field.
In terms of meeting up with David and telling Jason- if you are truly starting a serious relationship with this man, I think you owe it to him to be honest with him about your ex. If meeting with David will feel like sneaking, then you should tell Jason. If it won't, then perhaps you don't need to tell him.
Actually I kinda told him last night. I didn't exactly mean to, but it came out anyway.
We went to go see
Avatar which, by the way, was made of copious amounts of awesome. Afterwards, we went to a 24 hour diner and got seated at the bar. We were talking more about next week's events. And he explained that he will be gone from Christmas Eve until the 26th. He wanted to know if that was cool. I said, "Sure. I'm just gonna go hit some clubs and hop some bars." I then told him that I had an out-of-town friend coming in for Christmas to visit with family. Jason had been pretty busy eating his spaghetti but he did show some interest at this point. LOL He said "That's cool. Who is she?" I said it was actually a "He". He said, "Okay. Who is he?"
Jason has ice water in his veins.
So I just broke it down: I told him it was someone I was formerly in a relationship with, and that he had requested that I pick him up from the airport. I then reassured Jason that there is
nothing going on between this guy and me now, but we have been friends for over a decade, and I am very close with his family as well. I asked him "How do you feel about that?" He wiped his mouth as was like, "Is it okay if I think about it?" And I said, "Yeah. No problem."
Now I already know that Jason is thinking "Oh s***, we just got together and already we're entertaining exes from out of town." And that totally plays into his thing about M2M relationships not lasting long. But before I could really explain more about who this "person" is, some silly-ass black chicks came up to the bar (to cash out for their meals) and they started hitting on both of us. They were not really overt, but they were just getting all into our conversation and s***.

So that kinda broke the mood and we haven't discussed it since.
This situation has the potential to be very messy. Mainly because the house I am staying in now (where Jason has been sleeping over) is co-owned by David. We have not worked out all the assets/estate s*** yet, and he still has a key. Technically he even has a "right" to just come in, even though we already agreed that I'd be keeping this house under my name. That's why I told David that I was with someone and that he wouldn't be able to stay with me for any part of next week.
However, I think that Jason would like to know. It's important for him to know that you've really made a clean cut with David, and I think he'd respect you for telling him.
Well he knows. Whether he respects me or not for telling him remains to be seen. But I feel like I'm kinda protecting myself here by letting BOTH parties know what I'm doing with the other.