The most characteristic such combination is that of Aries with Taurus. These two zodiac signs can create a very beautiful relationship between them but unfortunately they will not stay faithful for long.
This couple does not believe in monogamy and does not consider themselves unfaithful because they have sex with other people. If they succeed and realize that they are very similar in this part of their relationship, then they can discuss their problem and maybe find a solution. Stopping being unfaithful is a solution that is usually not on their radar.
Other combinations of signs that do not stay faithful to each other:
# 1. Gemini-Libra
# 2. Cancer-Capricorn
# 3. Leo-Sagittarius
# 4. Scorpio-Pisces
# 5. Aquarius-Virgo