Is there a chance with this couple?

I don't know if this is the right place to ask this but here we go:

I am 24. I recently moved in with an unmarried couple, in their 30's. I rented their room and will be living at their place for 6 months. The guy is 29 and the woman is 37. They are cool people and very easy going.

It's always been my greatest fantasy to have threesome with a couple or with a woman when the husband or boyfriend is watching. I've seen many couples doing that but never had a chance to explore it myself.

Maybe it's a fantasy I am making up in my head, but I get the feeling that this couple has some intentions to do that. I got some signs that they are testing the waters with me but I cannot be very sure:

- When I am visiting their apartment for the first time, the guy asks me how old I am and when I tell them my age, he says "That's a good age for you, huh? Does that work?" and winks at her. She smiles in return.
- We are having a welcome dinner one night and I ask them how long they have been together. The girlfriend says they have known each other for seven years but she is bored of him and wants a younger guy. He says he will go for an older woman soon. They both add they love changing partners and trying new people. They say these in a teasing way but also sound very serious at the same time. I smile innocently and say "Oh, I am having new flatmates soon!" and they both laugh at it.
- They are very open about sex terms. I've heard them making jokes next to me, involving the words "ass, balls, penis, lesbian, gay".

It's only been a week and I am not sure if I should bring my hopes up or not. I am ok with just enjoying them as my flatmates and leaving the place happily but at the same time, I wouldn't want to miss an opportunity to spend some exciting evenings with them during these 6 months if they are up for it.

As you might guess, I am afraid of bringing it up, risking losing my only accomodation here and screwing up with their relationship.

I can understand that this could sound weird and unusual for some people here but I would like some advice on how to handle this situation without looking like a pervert who is after banging a guy's girlfriend. Please do not bother replying if you are gonna give me ethics lessons about how wrong it is to have an eye on a taken woman. I won't do that unless they want it to happen.