Is your gut telling you something?
When appearances become top priority
S/he suddenly changes hair style and perfume, gets a new wardrobe, and finds a renewed interest in fitness.
The lure of the virtual world
Your partner spends more time with virtual friends than with you and seems to follow/add as a friend a lot of new people you've never heard of.
Where's the love gone?
Your partner is less affectionate, and your intimate life is not what it used to be.
Not without my phone
In the kitchen, in front of the TV, in the bathroom, your partner always keeps his/her phone on him/her and always in silent mode. Yet you have difficulty reaching your partner during the day. You often go straight to the voicemail and your partner always has a new explanation for this lack of availability.
Your partner can be sweet and attentive one moment, and aggressive and distant the next. Your partner has a different body language and doesn't look you in the eye. He/her seems very uncomfortable when you ask questions about his/her schedule.
These are often signs that your partner is torn between the guilt of looking for a new encounter and the fact that you're keeping him/her from doing it.