texting female colleague at night

Do you think it is acceptable for husband to text his female colleague at night ? My husband has been texting his female colleague whom he said was his good friend at night .. i saw the convo, some are quite intense .. for example, the good friend said that my husband is spoiling her... , or my husband sending her to work and when she shared with my husband that her bf doesnt care when someone was hitting up on her , my husband response was "how dare he..".. Am i thinking too much...