"If at first" joke

At a resort, a fellow walks up to an older fellow who is sitting
in the sun, sipping iced tea.
Younger guy says - "Hey, you gonna just sit around all day? How
about it if you join me for a round of golf."
"Nah," the older fellow replies, "tried it once, didn't like it."
"Well then," younger fellow asks "how about a swim? It might be
just as refreshing as your iced tea there."
"Nah," the older fellow responds, "tried it once, didn't like it.
But if you're game for tennis, my son will be here soon and is
usually up for a game or two - you might want to play with him."
Younger fellow replies: "Your only child I presume?"
Rob Peck