I made a relationship with an ISFJ/INFJ work for 4 yrs.. which is a HUGE accomplishment for me! So I'm gonna give this a shot.
In private, I am very close to my girlfriend.. I enjoy lots of space, but I enjoy being close just as much. I like more light hearted convo and serious convo about things outside of us (news, thoughts, debates..)... conversations being too emotionally heavy can be VERY draining for me.. but I stick it through for her when it's needed because she needs that from me sometimes.
I enjoy relaxing and hanging out at home with her more than anything. I tell her I love her on a daily basis because I know that she likes to know that and she gets upset when I don't.. and I don't want to have to get the "you don't care no more" talk. I've learned to bend for her because I love her, in turn she tries to not be too emotional with me and gives me my freedom to do things outside of us.
In public.. around other people.. I become very quiet.. I don't usually have much to say to people I don't know very well. I let her go on and do her own thing I prefer to stay in one area and kind of blend into the background.. she thinks I get cold or upset because I don't like to get in there with her and talk a whole lot with her in front of people.
I just enjoy being in my own space with my own thoughts, if someone talks to me I will be more than happy to try to keep up a conversation.. but that's my idea of enjoying it.