Jennifer Aniston Seems to Confirm Romance in PDA-Packed Pics with Jim Curtis

Jennifer Aniston heating up those summer romance rumors with Jim Curtis ... 'cause he gave her a streamy massage while on a yacht trip!

The actress and the hypnotist were spotted together on a yacht off the coast of Mallorca ... wearing matching black shirts -- Jenn in a tank top and Jim in a collared number.

Jenn must've had a knot in her neck, 'cause Curtis puts his hands on her and starts rubbing away ... a move that could just be friendly -- though it seems to indicate there's more going on between the two of them.

Jason Bateman and Amy Schumer are also on the yacht, according to reports ... a big group couples trip it seems.

Us Weekly -- citing an anonymous source -- reported earlier week that the Jennifer and Jim are in a relationship ... and, vacationing in Europe together is no small step, even for an A-list coupling.

Again, neither Jennifer or Jim have formally confirmed the romance, as far as we can tell ... but, this is a pretty cut and dry relationship debut as far as we're concerned.