I was glad to meet him last night,for me____(not see) each other for a long time.

I was glad to meet him last night,for me____(not see) each other for a long time.
I was glad to meet him last night,for me____(not see) each other for a long time.

I was glad to meet him last night,for me____(not see) each other for a long time.
haven't seen
后面有明显的时间,所以应该用完成时

hadn't been seeing