Why go to meet-up parties if taken?

I have this situation and I would like some feedback from some of the Japanese men and women who may have been to these parties. I am utterly confused.
I have been with a guy for two years, engaged for one year and lately he attends a lot of ''International meet-up parties'' from various cultures. He says it is to find friends and exchange emails with new people from other countries. At first I thought it sounded cool as we both love learning about new cultures. Well, recently he said he was going to one and it included a dance along with info exchange and dinner. One friend of mine (a guy) told me that these parties are for meeting potential spouses, or gfs and bfs from other countries. That explanation makes a lot of sense now that I think about it and when I confronted my guy he got very appalled that I would suggest he could be doing anything wrong. I have not been to one of these parties as I am always too busy with work. I now wish I could go myself and see what they are about. Anyone here been to one? Are they really just about exchanging culture and friendship? Or are they hook-up parties (match-making type)?
I am really upset by this,and I would appreciate any feedback from anyone knowing about how the Japanese people attending the parties view them.
Thank in advance.

Take a day off of work and go to one of them and find out for yourself if you don't 100% trust him. Maybe he is indeed just interested in meeting international cultures and people, your boyfriend is Japanese and you are not Japanese right? That could be one reason. Depends on how well you trust him.

I used to organize cultural exchange parties, and a lot of the members were corny old people who were already married and wasn't interested in romance, although I do have a friend who got married through these parties we organized.

Parties vary and the way people use it vary too. As mentioned, you have to attend it to see for yourself.

I attended a few of these parties in Japan once because I was curious myself. It was all young people with only a few 30+ and seems most people were there to find potential friends/partners from other countries.
I had a problem with this as it was my then girlfriend going to it all the time. Some of the things I saw from other foreign guys made me mad but I turned a blind eye.

It was a good occasion to talk to other people, I think girls go there with the best intentions but Im not so sure about the guys hehe. I wont go to anymore

...but I wouldn't be happy if my partner was off meeting total strangers on a regular basis, especially if they all happen to fall on days where you are unable to attend. A 'dinner and dance' doesn't sound like an event made for 'meeting new friends' to me, even if that is how your partner views it.

Confront him about it. If he uses the old "don't you trust me" line, assure him that it's not him you are concerned about, but the intentions of those he meets. Insist on him going to some with you, and see what you think for yourself. He could be totally honest (in which case, make sure you apologise to him for assuming otherwise), but he could be playing you for a fool.

Better safe than sorry.

Depending on your line of business you're meeting total strangers every single day. Again go to one yourself and find out. Many different organizations arrange international meetings, from local city halls trying to get citizen involvment to indpendent organizations or individuals. So it varies greatly