>>98242804He fucks them all eventually.
He just had to wait for them all to get used to the idea of sharing him.
That's why Sasami and Washu are the best, they caught on quickly.
While Ryoko and Ayeka were fighting over which one of them would get to seduce Tenchi in the middle of the night, Sasami walked past them and Tenchi invited her into his room. And Washu was already there.