This is a person thing not a bodhran problem.
I have seen and suffered many a banjo and guitar intrusion as an a capella singer
I had to listen to a person at my regular club harmonise to every song with diminished sevenths all night. No amount of polite humour alters him. I for one breathed a sigh of relief when he joined a West Gallery Quire.
the bad news was that they knew more tuneful sevenths than he could shake a head at and they had more egoes than he could surmount. At the club the organisers have very definite and opinionated views about etiquette but then he is one of them. Ten years later I now live far enough away to dissaude me from visiting, but regulars include some very nice people who made the club vibrant when I was going through divorce, how can I desert them entirely? I chose to suffer his harmonies, I sing to give them enjoyment and if thats what they want, so be it. If I don't feel I can enjoy it any given I have to decline.

If you can't enrol the consensus of the body of the club, blame the club & go elsewhere. In the Uk we are blessed with such richness of sessions/clubs.
convince the bodhran that there is a SESSION down the road and see if he discovers where he should really be going.

AND what is the problem with two bodhrans? both mine are red.