Take it sloooooow. It's nice that you have a new lover and that there's potential there, but don't let the hormones and excitement overwhelm your priorities. If you move forward with an unstable base, it will all crumble and you will either a) lose the chance at this new relationship anyway, b) lose your current relationship, c) manage to keep them both but with a lot of avoidable angst and pain along the way.
Pull back, do a lot of talking with your partner, and don't rush into anything. It's like if you're heading off down a fun and exciting road and you hear a scary sound like maybe your tire just popped. Stop and check it out before you go on or you could crash! It'll be much easier to pause now than to have to pick yourselves out of the wreckage later. It may seem like I'm being melodramatic, but it happens all too often when one partner is excited and the other is scared and it doesn't really get resolved in time.
Wonderful resources on jealousy and more here: www.morethantwo.com
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.