Jiu-Jitsu Instructor with Gisele Bündchen Traveled to Train Kids for Home School

Gisele Bündchen and jiu-jitsu instructor Joaquim Valente have raised a lot of suspicion as to possible romantic ties, but we at least now know one of the reasons he's traveled with her to Costa Rica ... he's training her and Tom Brady's kids.

Sources close to Gisele tell us the kids, Benjamin and Vivian, are homeschooled and have a team travel with them to make sure they're receiving all the necessities for their education. We're told there's a full-time teacher who travels to teach the kids their basics -- and Valente as well -- it's also not the first time the group has made the trip to Costa Rica together.

Our sources say Valente handles the physical education aspect of the homeschooling -- which makes sense considering he's trained them in jiu-jitsu -- after connecting in Miami.

Nonetheless, it does feel odd Valente was able to up and leave his jiu-jitsu biz back home for several weeks while he's with Gisele and crew ... though you gotta imagine the money is good.

While it's not 100% clear where Gisele and Joaquim stand, we still haven't seen any PDA, and our Gisele sources are adamant -- there's nothing romantic. However, one source close to the former couple still believes the timing of the trip is interesting considering her and Tom just finalized their divorce.