Tahm Kench can devour me forever

I was playing a game against Tahm Kench. Our minions were pushing their nexus towers and it was just him and me. He was the support so I was pretty much ignoring him as I tried to take his towers. Then he swallowed me up. I thought whatever, he cant hang onto me for long anyways right? He spits me out again, I get an auto or two off and then he swallows me again. I actually couldn't do anything about it. If I tried to even run away he would slow me and then swallow me back up.

I think that's pretty ridiculous.