Great Kisser is one of the many traits in the Sims Social. According to the in-game description, "Great kissers tend to have more success than the rest."
What this means is that it is that your Sim will be rejected less often when they initiate romantic social actions. This makes it easier to increase the level of your romantic relationship with Sims.
Having this trait also unlocks the romantic social action: "Steamy Makeout".
Levels[]
Level
Cost to Upgrade
Description
Benefits
1
150
Less likely to get a slap in the face for a kiss than average.
Have a less chance of failing at kissing.
2
300
Kiss with confidence.
Have a better chance of kissing.
3
700
In a relationship? Try the exclusive Steamy Make Out.
Have a new interaction - 'Steamy Makeout'
4
1000
Effortless kisser.
Even less chance of failing and double the normal relationship.
5
1500
Kissing is a weapon this Sim wields with devastating effect.