If you do not see yourself marrying or being with someone for a lifetime, please don't court her.
If you do not see yourself loving and staying with him all the time, for life, never give him hope, nor allow him to pursue you.
Being in a relationship is an obligation and choice. You need to be firm on loving and choosing each other despite all odds, including temptations. You have to be consistent and constant with your love and intentions. Otherwise, it will not last.
Realizations