I'd boil it down to 2 versions:

"А он симпатичный! Правда?" - "uh on simpatichniy! Pravda?"

"Правда он симпатяшка?" - "Pravda on simpatyashka?"

Милый and красивый would not be equivalet to "cute" here.
The highlighted vowels are stressed.
The second one seems to be real hard for beginners (I was trying to get one American guy say "симпатяшка" for a couple of days, but gave up eventually )