soft swap where i may as well not have been in the room

so. our first proper swap in glasgow last weekend. husbands separate rooms, i stayed with the other wife and her bloke. he was sweet at first but the second things started he was just laser focused on her. like i was a prop. she kept trying to pull me in and he kept gently moving past me like i was furniture. i ended up just sat on the edge of the bed watching them, fully clothed half hour in. nobody noticed. nobody asked. my husband came back glowing she came back glowing he came back glowing and im sat in the uber wondering if i imagined how invisible i felt. is this normal for first times or did i pick wrong. 38, hes 40, been talking about this for years finally tried it