How can you call a big bet pre-flop with 5-8 suited?

That's what the new guy at PKR asked me..... How can you call a big bet pre-flop with 5-8 suited? Well, he had recently stayed in with a garbage hand to a large raise that I made pre-flop and took down the pot by hitting one of them with trips. So it was lesson time at PKR. Again... $1-$2 No Limit. I look down at 5d, 8d. The new guy is in the big blind and after about 7 limpers including me, he raised it to $16. There were 4 callers and I thought that this could be a great opportunity to get lucky so I called. The flop comes 6s, 7c, 9s. Not the nuts, but I loved it! The new guy bets $25 and there is one caller and I call. The turn is a 2d and our new guy bets $50 and I'm the only caller. The river is a Qh and my new best friend goes all in for about $120 more. I immediately call and turn over the 2nd nut straight. He shows his aces and immediately requires therapy and help with his breathing. I love this game!