Welcome to our forum.
It is wonderful to hear about when a V comes together so smoothly; it doesn't always happen like that. If you hit some bumps in the road the next few years, don't be discouraged; that often happens to new poly units. You get each other's quirks figured out, and eventually things settle into what I call the "blissfully boring" (no drama).
The other "arm of your V" sounds like a great guy, and it helps a lot that you two guys already have a strong friendship. Hey you both obviously have awesome taste in women, right?
I hope Polyamory.com is a good help for you in times of need, and during the good times as well. Have a look at our various threads and see what calls to you; post any thoughts or questions that you may have.
Good to have you aboard.