Relationship between type 7 and type 3

The epicurean and the chameleon

Tyrion Lannister (GOT)
Mary Crawley (Downton Abbey)

Attraction

It is a relationship full of adventure and very complementary.
The 3 is attracted by the playful, adventurous, spontaneous, enthusiastic, and fun spirit of 7. As well as his humor, his lightness and his insight.
The 7 is attracted by the charm, self-confidence, sociability and prestige of the 3. As well as his enthusiasm and his ability to accompany him in his adventures.
Both are optimistic, open, active, independent, friendly, social, energetic, and want a life full of different and fulfilling experiences.

Points where to be careful

The 7 can sometimes find that the 3 pays too much attention to his success and social image instead of letting go and having more fun with him.
The 3 can sometimes see 7 as being too irresponsible, unstable and undisciplined.